Radiofrequency (RF) electrode catheters have been in common use in medical practice for many years. They are used to stimulate and map electrical activity in the heart and to ablate sites of aberrant electrical activity. Specifically, targeted ablation may be performed for a number of indications. For example, ablation of myocardial tissue is well known as a treatment for cardiac arrhythmias by using a catheter to apply RF energy and create a lesion to break arrhythmogenic current paths in the cardiac tissue. As another example, a renal ablation procedure may involve the insertion of a catheter having an electrode at its distal end into a renal artery in order to complete a circumferential lesion in the artery in order to denervate the artery for the treatment of hypertension.
In many of these procedures, a basket shaped electrode catheter is used. Basket shaped catheters have several spines or arms connected together at both of their proximal and distal ends. In many of these basket shaped catheters, movement of these spines into a basket is done by longitudinal translation of a pull-wire connected to the distal ends of the spines. The pull-wire extends the length of the catheter, from the proximal handle to the multitude of spines. One problem with these arrangements is that the lumen housing the pull-wire is an open lumen, allowing irrigation fluid as well as bodily fluids to move into the lumen. Exposure of the proximal end of the catheter body to fluids may interfere with the wires electrically connecting the electrodes and sensors to the control panel causing a disruption of the procedure. Prior art catheters have attempted to prevent the back-flow of fluids into the pull-wire lumen using an O-ring or liquid sealant, but these have proven unsuccessful.
Accordingly, it would be desirable to provide an irrigated ablation catheter that has an improved sealing arrangement for the pull-wire lumen that overcomes these and other disadvantages. As will be described in the following materials, this disclosure satisfies these and other needs.